CA1144880A - Composite container with balloon fold - Google Patents
Composite container with balloon foldInfo
- Publication number
- CA1144880A CA1144880A CA000363100A CA363100A CA1144880A CA 1144880 A CA1144880 A CA 1144880A CA 000363100 A CA000363100 A CA 000363100A CA 363100 A CA363100 A CA 363100A CA 1144880 A CA1144880 A CA 1144880A
- Authority
- CA
- Canada
- Prior art keywords
- liner
- container
- fold
- edge portion
- bonded
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D3/00—Rigid or semi-rigid containers having bodies or peripheral walls of curved or partially-curved cross-section made by winding or bending paper without folding along defined lines
- B65D3/22—Rigid or semi-rigid containers having bodies or peripheral walls of curved or partially-curved cross-section made by winding or bending paper without folding along defined lines with double walls; with walls incorporating air-chambers; with walls made of laminated material
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Packages (AREA)
- Making Paper Articles (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A composite container capable of accommodating an internal vacuum environment within a tubular body of spirally wound paperboard or similar paperbase materials. A
hermetically sealed liner is provided coextensive with the interior of the tubular body and adhesively secured thereto throughout substantially the full extent of the interior surface of the body. The liner is spirally wound, defining a spiral overlapped seam with the overlapping edge portion including an underfolded edge flap folded about a fold line prior to adhesive engagement with the overlapped edge portion.
The seam fold thus formed has the interior thereof in direct communication with the paperbase body and is capable of ballooning inward, through the entire length thereof, upon generation of a vacuum atmosphere with the container. The vacuum atmosphere can thus be accommodated without affecting the structural integrity of the container. Lines of weakness are specifically avoided in the body plies by staggering the ply seams, offsetting the ply seams from the liner balloon seam, and providing at least some of the body plies with overlapped deckled or skived edges.
A composite container capable of accommodating an internal vacuum environment within a tubular body of spirally wound paperboard or similar paperbase materials. A
hermetically sealed liner is provided coextensive with the interior of the tubular body and adhesively secured thereto throughout substantially the full extent of the interior surface of the body. The liner is spirally wound, defining a spiral overlapped seam with the overlapping edge portion including an underfolded edge flap folded about a fold line prior to adhesive engagement with the overlapped edge portion.
The seam fold thus formed has the interior thereof in direct communication with the paperbase body and is capable of ballooning inward, through the entire length thereof, upon generation of a vacuum atmosphere with the container. The vacuum atmosphere can thus be accommodated without affecting the structural integrity of the container. Lines of weakness are specifically avoided in the body plies by staggering the ply seams, offsetting the ply seams from the liner balloon seam, and providing at least some of the body plies with overlapped deckled or skived edges.
Description
B KGROUND OF THE INVENTI~N
The present invention is generally concexned with lined composite can construction, and more particularly with the construction of composite cans in a manner so as to accommodate a reduced internal pressure or an internal vacuum environment.
Substantial advantages of both an economic and environmental nature reside in the use of composite con-tainers as opposed to the more traditional glass and metal containers.
Such advantages include reduced expenses both in the materials used and in the procedures involved in the manufacture of the container. Also, and of particular significance, is the fact that composite containers are, to a large extent, biodegradeable and easily disposed of without adversely affecting the environment. However, the use of composite containers is, to an appreciable degree, limited because of the lack of inherent strength in such containers.
A particular area of difficulty is the packaging of products which either inherently produce or require the formation of an internal vacuum environment. As a specific example, in the hot filling of lined composite containers of conventional construction with single strength juice, such as orange, grapefruit and grape juicest there is a substantial likelihood of the cans imploding. The hot filling of these juices into the containers involves direct introduction of the juice from the pasteurizing apparatus into the cans at a liquid temperature of from 190 to 200 Farenheit. After ~illing, the tops are applied and seamed to the cans and the cans subsequently cooled to less than 100 Farenheit. This cooling creates an internal vacuum of approximately 15 inches of mercury. The pressure differential created by -the vacuum environment formed within the can in turn gives rise to a very substantial likelihood the can or container will implode.
At the very least, air under the higher external or ambient pressure will seep through the fibrous body of the can and act directly against the inner hermetic foil liner. This pressure against the liner, even when provided with a kraft paper backing, will cause a tearing of the liner away from the fibrous body, resulting in an uncontrolled inward blistering, or in . ~,.
8~3~
fact rupturing, of the liner.
A further discussion of the desirability of the use of composite cans, the problems inherent therein when dealing with vacuum packaging, and one solution Eor the accommodation of vacuum packaging in composite cans, will be found in Applicant's prior United States Patent No. 4,158,425 dated June l9th, 1979 and issued to Sonoco Products Company entitled "Composite Container Construction".
The present invention proposes composite can construction particularly adapted for accommodating hot fill single strength juices which inherently generate a reduced internal pressure or vacuum environment when following conventional can filling procedures. The proposed construction is compatible with the use of available spiral winding apparatus and conventional composi-te container forming materials including paperbase body plies, outer labels of any appropriate material, and inner hermetic liners normally formed of metallic foil backed by strengthening kraft paper and, if desired, faced by thin plastic film for enhancing the air impermeable nature thereof.
The accommodation of the internal vacuum is provided for by forming the liner in a manner whereby a controlled inward ballooning of a selected portion of the liner takes place. This inward ballooning, while sufficient to accommodate the pressure differential without destruction of the liner, does so in a manner whereby substantially the entire liner remains ~irmly adhered to the inside of the fibrous body wall. In this manner, a s-table product confining interior is retained.
In order to provide for the desired controlled inward ballooning of a selec-ted portion of the liner, the spirally formed seam is provided with an excess fold, the interior of which is in direct communica-tion with the multi-ply paperbase body. The fold is formed by a reverse or underfolding of a full length edge flap of the overlapped liner edge provided as a result of the spiral winding of the liner. The under-folded edge flap is thus positioned with the foil facing thereof in direct contact with the foil facing of the immediately underlying edge portion. A continuous full-length adhesive bond is provided between these facing edge surfaces with the fold extending beyond the area of adhesive bonding into free overlying relation with the area of the liner immediately adjacent the bonded portion edge surfaces.
The back face of the liner is bonded along substantially the entire surface thereof -to the inner face of the body as the body plies are spirally wound about the initially formed liner. The only area wherein there is no direct bonding between the liner and the body is immediately ou-tward of the adhesive bond between the overlying edges for a narrow width which extends along the full length of the seam. In this manner direct communica-tion is provided between the body plies and the interior of the excess fold. This unbonded area may actually be formed by the minute spacing provided immediately adjacent the overlapping edges when the innermost edge portion is slightly inwardly offset from the body plies to achieve the overlap.
The unbonded area provides a specific air passage to the interior of the excess fold whereby air permeating the body plies, because of the vacuum generated pressure differential, will pass into and inwardly balloon the excess fold. This will enable an effective reduction in both the excess area within the can and the pressure generating vacuum in a controlled manner along the full length and around the circumference of the can without any danger of imploding rupture of the liner, contamination of the product, or leakage.
It is considered particularly significant that the basic structural integrity of the can be maintained constant throughout the full extent thereof, with there being no inherent lines of weakness, notwithstanding the provision of a ballooning fold within the liner itself. Accordingly, it is specifica]lv provided that the liner seam, with excess fold, be substantially offset from the body ply seam or seams.
In turn, the body seams are to be bonded, and in some or all instances actually skived or deckled, in a manner whereby the body forms a constant strength tubular construction throughout the length thereof. As an additional expedient/ if deemed desirable, the outer or labeled ply can also have the seam thereof offset from both the body ply seams and the liner seam.
- ~ -It is believed additional objects and advantages will become apparent from the following more detailed description of the construction involved in the present invention.
Embodiments of the invention will now be described with refrence to -the accompanying drawings in which:
Figure 1 is a perspective view of a container or can, with the top removed, formed in accordance with the present invention and illustrating -the balloon fold in its expanded position;
Figure 2 is an enlarged cross-sectional detail through the can structure illustrating the balloon fold prior to the expansion thereof in response to an internally generated vacuum, Figure 3 is a view similar to Figure 2 with the fold in its inwardly expanded or ballooned position;
Figure 4 is a side elevational view, with a portion broken away, illustrating a can immediately upon the filling and sealing thereof with the inherently provided head space and the unexpanded seam fold;
Figure 5 is a view similar to Figure 4 wherein the internal vacuum, and hence the developed pressure differential, has effected an expansion of the balloon fold and an accommoda-tion of the product in -the initially provided head space; and Figure 6 (which is on the same page of drawings as Figures 1, 2 and 3) is a schematic illustration of the formation of a can in accordance with the present invention.
Referring now more specifically to the drawings, reference numeral 10 is used to generally designate a composite can constructed in accordance with the present invention.
Noting the cross-sectional details of Figures 2 and 3, the construction of the container involves the provision of a paperboard or paperbase body 12 formed of a-t least one and normally multiple spirally wound plies provided with edge seams 14 specifically formed to provide a high degree of structural in-tegrity whereby the body of the can will be of substantially equal s-trength through the full extent thereof.
This provision of a full strength seam will normally-involve a direct bonding of the seam edges and an actual skiving or deckling of all or selecte-l ones of the body ply edges for a ~ ~ 4~
positive overlapped bonding thereof. Finally, the edge seams of the individual body plies can be slightly staggered relative to each other to avoid a direct stacking thereof and thus enhance the strength of the body. An appropriate label or finishing ply 16 will normally be spirally formed about the exterior of the body 12 and intimately bonded thereto by an appropria-te adhesive layer 18.
The wall construction of the container or can 10 is completed by the internal liner 20, the structural u~iqueness of which, in conjunction with the relationship to the multi-ply body 12, contributes significantly to the invention and the advantages flowing therefrom.
The liner 20 is to be of a material capable of providing a hermetic seal for the interior of -the can. As such, an appropriate liner would comprise a metallic foil directed inward toward the interior of the can with a strengthening backing of kraft paper or the like bonded thereto and adapted to be in turn bonded to the inner surface of the body 12. If deemed desirable, an appropriate plastic film can be provided over the foil face to further enhance the impermeability thereof.
The liner 20 is spirally formed with the edges thereof overlapped and hermetically sealed.
Noting Figure 2 in particular, the overlapped liner edge portions include, relative to the interior of the can, an underlying outer edge portion 22 and an overlying inner edge portion 24. The overlying inner edge portion 24 has an extreme edge Elap 26 along the full length thereof folded under whereby the foil face of this overlying edge flap faces the foil or inner surface of the underlying edge portion 22. The facing foil surfaces are hermetically sealed along the full length thereof by an appropriate adhesive stripe or other bonding means 28. The inner facing surfaces 30 and 32 between the folded edge flap 26 and the corresponding edge portion 24 remain unbonded and free to move relative to each other as will be best appreciated from a comparison of Figure 3 with Figure
The present invention is generally concexned with lined composite can construction, and more particularly with the construction of composite cans in a manner so as to accommodate a reduced internal pressure or an internal vacuum environment.
Substantial advantages of both an economic and environmental nature reside in the use of composite con-tainers as opposed to the more traditional glass and metal containers.
Such advantages include reduced expenses both in the materials used and in the procedures involved in the manufacture of the container. Also, and of particular significance, is the fact that composite containers are, to a large extent, biodegradeable and easily disposed of without adversely affecting the environment. However, the use of composite containers is, to an appreciable degree, limited because of the lack of inherent strength in such containers.
A particular area of difficulty is the packaging of products which either inherently produce or require the formation of an internal vacuum environment. As a specific example, in the hot filling of lined composite containers of conventional construction with single strength juice, such as orange, grapefruit and grape juicest there is a substantial likelihood of the cans imploding. The hot filling of these juices into the containers involves direct introduction of the juice from the pasteurizing apparatus into the cans at a liquid temperature of from 190 to 200 Farenheit. After ~illing, the tops are applied and seamed to the cans and the cans subsequently cooled to less than 100 Farenheit. This cooling creates an internal vacuum of approximately 15 inches of mercury. The pressure differential created by -the vacuum environment formed within the can in turn gives rise to a very substantial likelihood the can or container will implode.
At the very least, air under the higher external or ambient pressure will seep through the fibrous body of the can and act directly against the inner hermetic foil liner. This pressure against the liner, even when provided with a kraft paper backing, will cause a tearing of the liner away from the fibrous body, resulting in an uncontrolled inward blistering, or in . ~,.
8~3~
fact rupturing, of the liner.
A further discussion of the desirability of the use of composite cans, the problems inherent therein when dealing with vacuum packaging, and one solution Eor the accommodation of vacuum packaging in composite cans, will be found in Applicant's prior United States Patent No. 4,158,425 dated June l9th, 1979 and issued to Sonoco Products Company entitled "Composite Container Construction".
The present invention proposes composite can construction particularly adapted for accommodating hot fill single strength juices which inherently generate a reduced internal pressure or vacuum environment when following conventional can filling procedures. The proposed construction is compatible with the use of available spiral winding apparatus and conventional composi-te container forming materials including paperbase body plies, outer labels of any appropriate material, and inner hermetic liners normally formed of metallic foil backed by strengthening kraft paper and, if desired, faced by thin plastic film for enhancing the air impermeable nature thereof.
The accommodation of the internal vacuum is provided for by forming the liner in a manner whereby a controlled inward ballooning of a selected portion of the liner takes place. This inward ballooning, while sufficient to accommodate the pressure differential without destruction of the liner, does so in a manner whereby substantially the entire liner remains ~irmly adhered to the inside of the fibrous body wall. In this manner, a s-table product confining interior is retained.
In order to provide for the desired controlled inward ballooning of a selec-ted portion of the liner, the spirally formed seam is provided with an excess fold, the interior of which is in direct communica-tion with the multi-ply paperbase body. The fold is formed by a reverse or underfolding of a full length edge flap of the overlapped liner edge provided as a result of the spiral winding of the liner. The under-folded edge flap is thus positioned with the foil facing thereof in direct contact with the foil facing of the immediately underlying edge portion. A continuous full-length adhesive bond is provided between these facing edge surfaces with the fold extending beyond the area of adhesive bonding into free overlying relation with the area of the liner immediately adjacent the bonded portion edge surfaces.
The back face of the liner is bonded along substantially the entire surface thereof -to the inner face of the body as the body plies are spirally wound about the initially formed liner. The only area wherein there is no direct bonding between the liner and the body is immediately ou-tward of the adhesive bond between the overlying edges for a narrow width which extends along the full length of the seam. In this manner direct communica-tion is provided between the body plies and the interior of the excess fold. This unbonded area may actually be formed by the minute spacing provided immediately adjacent the overlapping edges when the innermost edge portion is slightly inwardly offset from the body plies to achieve the overlap.
The unbonded area provides a specific air passage to the interior of the excess fold whereby air permeating the body plies, because of the vacuum generated pressure differential, will pass into and inwardly balloon the excess fold. This will enable an effective reduction in both the excess area within the can and the pressure generating vacuum in a controlled manner along the full length and around the circumference of the can without any danger of imploding rupture of the liner, contamination of the product, or leakage.
It is considered particularly significant that the basic structural integrity of the can be maintained constant throughout the full extent thereof, with there being no inherent lines of weakness, notwithstanding the provision of a ballooning fold within the liner itself. Accordingly, it is specifica]lv provided that the liner seam, with excess fold, be substantially offset from the body ply seam or seams.
In turn, the body seams are to be bonded, and in some or all instances actually skived or deckled, in a manner whereby the body forms a constant strength tubular construction throughout the length thereof. As an additional expedient/ if deemed desirable, the outer or labeled ply can also have the seam thereof offset from both the body ply seams and the liner seam.
- ~ -It is believed additional objects and advantages will become apparent from the following more detailed description of the construction involved in the present invention.
Embodiments of the invention will now be described with refrence to -the accompanying drawings in which:
Figure 1 is a perspective view of a container or can, with the top removed, formed in accordance with the present invention and illustrating -the balloon fold in its expanded position;
Figure 2 is an enlarged cross-sectional detail through the can structure illustrating the balloon fold prior to the expansion thereof in response to an internally generated vacuum, Figure 3 is a view similar to Figure 2 with the fold in its inwardly expanded or ballooned position;
Figure 4 is a side elevational view, with a portion broken away, illustrating a can immediately upon the filling and sealing thereof with the inherently provided head space and the unexpanded seam fold;
Figure 5 is a view similar to Figure 4 wherein the internal vacuum, and hence the developed pressure differential, has effected an expansion of the balloon fold and an accommoda-tion of the product in -the initially provided head space; and Figure 6 (which is on the same page of drawings as Figures 1, 2 and 3) is a schematic illustration of the formation of a can in accordance with the present invention.
Referring now more specifically to the drawings, reference numeral 10 is used to generally designate a composite can constructed in accordance with the present invention.
Noting the cross-sectional details of Figures 2 and 3, the construction of the container involves the provision of a paperboard or paperbase body 12 formed of a-t least one and normally multiple spirally wound plies provided with edge seams 14 specifically formed to provide a high degree of structural in-tegrity whereby the body of the can will be of substantially equal s-trength through the full extent thereof.
This provision of a full strength seam will normally-involve a direct bonding of the seam edges and an actual skiving or deckling of all or selecte-l ones of the body ply edges for a ~ ~ 4~
positive overlapped bonding thereof. Finally, the edge seams of the individual body plies can be slightly staggered relative to each other to avoid a direct stacking thereof and thus enhance the strength of the body. An appropriate label or finishing ply 16 will normally be spirally formed about the exterior of the body 12 and intimately bonded thereto by an appropria-te adhesive layer 18.
The wall construction of the container or can 10 is completed by the internal liner 20, the structural u~iqueness of which, in conjunction with the relationship to the multi-ply body 12, contributes significantly to the invention and the advantages flowing therefrom.
The liner 20 is to be of a material capable of providing a hermetic seal for the interior of -the can. As such, an appropriate liner would comprise a metallic foil directed inward toward the interior of the can with a strengthening backing of kraft paper or the like bonded thereto and adapted to be in turn bonded to the inner surface of the body 12. If deemed desirable, an appropriate plastic film can be provided over the foil face to further enhance the impermeability thereof.
The liner 20 is spirally formed with the edges thereof overlapped and hermetically sealed.
Noting Figure 2 in particular, the overlapped liner edge portions include, relative to the interior of the can, an underlying outer edge portion 22 and an overlying inner edge portion 24. The overlying inner edge portion 24 has an extreme edge Elap 26 along the full length thereof folded under whereby the foil face of this overlying edge flap faces the foil or inner surface of the underlying edge portion 22. The facing foil surfaces are hermetically sealed along the full length thereof by an appropriate adhesive stripe or other bonding means 28. The inner facing surfaces 30 and 32 between the folded edge flap 26 and the corresponding edge portion 24 remain unbonded and free to move relative to each other as will be best appreciated from a comparison of Figure 3 with Figure
2. In addition, it will be noted that the width of the band of adhesive 28 is relatively narrow when compared -to the width of the fold, this band 28 being only sufficient to provide for a positive hermetic sealing of the edge portions. The fold itself projects in free overlying relation to the underlying edge portion 22 beyond the adhesive band 28 to provide a predeterrnined amount of excess material to achieve the desired ballooning as shall be explained subsequently.
The liner 20 is adhesively secured or otherwise bonded as at 34, to the interior surface of the body 12 throughout the full extent of the engaging surfaces thereof except for a narrow area 36 extending along the full length of the formed seam immediately outward of the free edge of the folded edge flap 26, opposed from the fold 38 itself, and in direct communication with the interior of the fold between the unsecured faces thereof. This enables passage of air through the porous multi-ply body, through the full length area 36, and into the fold for effecting an inward ballooning thereof as will be best noted in Figure 3. As a matter of manufacturing expedience, the narrow unbonded area 36 may be formed by the slight inward offsetting of -the inner edge portion 24 necessary so as to effect an overlapping of the outer edge portion 22.
While the plies of the body 12 may be slightly compressed during the construction of the can, as will be noted by the slight offset illustrated in Figures 2 and 3, this will not be sufficient to bring the overlapping edge portion 24 into bond-ing engagement with the inner surface of the body 12 irQmediately adjacent the underlying edge portion 22, thus ensuring the provision of the required narrow unbonded area 36.
The actual construction of the can 10 will normally ; be effected on substantially conventional spiral winding apparatus 40 as suggested in Figure 6. This will involve an initial spiral winding of the liner 20, including the folding of the liner edge as at 42, for a forming of the seam with the excess fold therein. The formation of the liner will, as a continuing process, be followed by a spiral winding oE the multiple plies which constitute the body 12 with the body ply seams offset from the liner seam. This in turn may be followed by a spiral winding of the cover ply or label. The product thus produced is a continuous tubular construction from which the individual cans are severed as at 44. An end plate or cap is sealed to one end of each of the individual cans and, at some later stage, the product introduced into the can and the second end thereof sealed. Until such time as the can is finally sealed with the product therein and the vacuum generated, the seam remains in its flattened condition as illustrated in Figure 2.
As previously referred to, the can of the present invention is particularly intended for use with products packed under vacuum conditions or conditions whereby an internal vacuum environment is produced. A primary example of this is single strength juices such as orange, grapefruit and grape juices which are filled into cans from pasteurizing appara~us at a liquid temperature of approximately 190 to 200 Farenheit.
After filling, the open end is hermetically sealed, involving a seaming procedure wherein the impermeable lid directly seals to the liner itself. Next, the individual cans are cooled down to less than 100 Farenheit. This creates an internal vacuum of approxima-tely 15 inches of mercury. Figure 4 generally illustrates a can filled as above immediately subsequent to the sealing of the can and prior to the cooling thereof. It will be noted that, as is conventional in filling containers with products of all types, and in particular juices, a head space 46 remains.
The generation of an internal vacuum environment produces a substantial pressure differential between the interior and exterior of the can. This pressure differential is so great as to cause, or at least give rise to the substantial possibility of causing, an implosion of composite cans of conventional construction. Even were the can body of sufficient stability to withstand imploding, air seeping under pressure through the paperbase body 12 would cause an inward blistering and/or rupturing of the air impermeable liner. The aforedescrihed excess fold seam is specifically provided to accommodate the pressure differential and avoid a destructive disruption of the can or liner. This accommodation of the pressure differential is achieved without affecting the s-tructural integrity of the container, without affecting the appearance of the container, and in a manner which more completely accommodates the product to the container, producing a firmex and more structurally stable package.
After a complete sealing of the can and a cooling thereof, the resultant pressure differential will result in the condition illustrated in Figure 5. More specifically, there will be a pressure induced seepage of air inwardly through the paperboard body 12 and through the spiral unbounded area 36, immediately at the excess fold seam, into the interior of the excess fold. This will cause a controlled inward ballooning of the fold along the full length of the spiral seam between the opposed end cap sealed ends thereof. The inward ballooning of the fold will be symmetrically provided both circumferentially and longitudinally about the container interior. The liquid or product displaced by the inward ballooning fold will be accommodated in the initially provided air head space above the liquid, with the inward controlled ballooning of the liner fold causing an effective reduction of the vacuum level and a relieving of the pressure differential f which in turn eliminates any possibility of container implosion or liner rupture. This in turn avoids any problems with regard to produce leakage, contamination, or the like.
The amoun-t of excess liner fold, that is the width of the foldl required is dependent upon the Eilled height of the liquid product and the resultan-t air head space remaining in the can between the can end and the liquid level. The following chart illustrates the width of excess fold required to completely void the vacuum created for various head space heights and volumes in different contempla-ted hot filled cans:
Head Space Height Volume Excess Fold Can Size (Inches) tCubic Inches) (Inches width required) ~02 x 314 (60z.) .125 .416 .467 " " .1875.624 .572 " " .250 .832 .660 " " .3751.247 .810 ~ " .5001.663 933 211 x 413 (120z.) .125 .649 .500 " " .1875.973 .618 " " .2501.297 .715 " " .3751.946 .875 " " .5002.595 1.00 404 x 700 (460z.) .125 1.687 .594 " " .18752.53 .728 " " .250 3.37 .841 " " .375 5.06 1.03 " " .5006.747 1.189 From the foregoing, it will be appreciated that a unique system has been devised for enabling the utilization of composite cans, of basically conventional strength, so as to accommoda-te products wherein a vacuum generated pressure differential is involved. Such a pressure differential, in the conventional can and without the features of the present invention, would, upon the generation of an internal vacuum, ; quite likely cause the can to implode, deform, rupture, leak or otherwise fail. Such problems are avoided by the contemplated provision of a ballooning fold within the liner seam assembly, in conjunction with a container body wall which 0 i5 of substantially constant strength, without lines of weakness, and capable of effectively retaining the product therein in the absence of excess pressure differentials.
In order to insure the structural integrity of the can, and in fact the complete package, specific provision is made to offset the liner seam from the seam or seams of the body ply or plies. In this manner, there is an avoidance of any weakness which might develop because of a stacked alignment . of the seams, notwithstanding the aforementioned intention . that the seams of the body plies be so constructed as to possess 20 an inherent strength equal to that of the body itself remote from the seams thereof.
~ The foregoing is considered illustrative of the ~ principals of the invention. As modifications may occur to those skilled in the art, it is not desired to limit the : invention to the exact embodiment or a manner of construction as shown and described. Accordingly, all suitable modifica-tiGnS and equivalents are considered appropriate within the scope of the invention as claimed.
.,
The liner 20 is adhesively secured or otherwise bonded as at 34, to the interior surface of the body 12 throughout the full extent of the engaging surfaces thereof except for a narrow area 36 extending along the full length of the formed seam immediately outward of the free edge of the folded edge flap 26, opposed from the fold 38 itself, and in direct communication with the interior of the fold between the unsecured faces thereof. This enables passage of air through the porous multi-ply body, through the full length area 36, and into the fold for effecting an inward ballooning thereof as will be best noted in Figure 3. As a matter of manufacturing expedience, the narrow unbonded area 36 may be formed by the slight inward offsetting of -the inner edge portion 24 necessary so as to effect an overlapping of the outer edge portion 22.
While the plies of the body 12 may be slightly compressed during the construction of the can, as will be noted by the slight offset illustrated in Figures 2 and 3, this will not be sufficient to bring the overlapping edge portion 24 into bond-ing engagement with the inner surface of the body 12 irQmediately adjacent the underlying edge portion 22, thus ensuring the provision of the required narrow unbonded area 36.
The actual construction of the can 10 will normally ; be effected on substantially conventional spiral winding apparatus 40 as suggested in Figure 6. This will involve an initial spiral winding of the liner 20, including the folding of the liner edge as at 42, for a forming of the seam with the excess fold therein. The formation of the liner will, as a continuing process, be followed by a spiral winding oE the multiple plies which constitute the body 12 with the body ply seams offset from the liner seam. This in turn may be followed by a spiral winding of the cover ply or label. The product thus produced is a continuous tubular construction from which the individual cans are severed as at 44. An end plate or cap is sealed to one end of each of the individual cans and, at some later stage, the product introduced into the can and the second end thereof sealed. Until such time as the can is finally sealed with the product therein and the vacuum generated, the seam remains in its flattened condition as illustrated in Figure 2.
As previously referred to, the can of the present invention is particularly intended for use with products packed under vacuum conditions or conditions whereby an internal vacuum environment is produced. A primary example of this is single strength juices such as orange, grapefruit and grape juices which are filled into cans from pasteurizing appara~us at a liquid temperature of approximately 190 to 200 Farenheit.
After filling, the open end is hermetically sealed, involving a seaming procedure wherein the impermeable lid directly seals to the liner itself. Next, the individual cans are cooled down to less than 100 Farenheit. This creates an internal vacuum of approxima-tely 15 inches of mercury. Figure 4 generally illustrates a can filled as above immediately subsequent to the sealing of the can and prior to the cooling thereof. It will be noted that, as is conventional in filling containers with products of all types, and in particular juices, a head space 46 remains.
The generation of an internal vacuum environment produces a substantial pressure differential between the interior and exterior of the can. This pressure differential is so great as to cause, or at least give rise to the substantial possibility of causing, an implosion of composite cans of conventional construction. Even were the can body of sufficient stability to withstand imploding, air seeping under pressure through the paperbase body 12 would cause an inward blistering and/or rupturing of the air impermeable liner. The aforedescrihed excess fold seam is specifically provided to accommodate the pressure differential and avoid a destructive disruption of the can or liner. This accommodation of the pressure differential is achieved without affecting the s-tructural integrity of the container, without affecting the appearance of the container, and in a manner which more completely accommodates the product to the container, producing a firmex and more structurally stable package.
After a complete sealing of the can and a cooling thereof, the resultant pressure differential will result in the condition illustrated in Figure 5. More specifically, there will be a pressure induced seepage of air inwardly through the paperboard body 12 and through the spiral unbounded area 36, immediately at the excess fold seam, into the interior of the excess fold. This will cause a controlled inward ballooning of the fold along the full length of the spiral seam between the opposed end cap sealed ends thereof. The inward ballooning of the fold will be symmetrically provided both circumferentially and longitudinally about the container interior. The liquid or product displaced by the inward ballooning fold will be accommodated in the initially provided air head space above the liquid, with the inward controlled ballooning of the liner fold causing an effective reduction of the vacuum level and a relieving of the pressure differential f which in turn eliminates any possibility of container implosion or liner rupture. This in turn avoids any problems with regard to produce leakage, contamination, or the like.
The amoun-t of excess liner fold, that is the width of the foldl required is dependent upon the Eilled height of the liquid product and the resultan-t air head space remaining in the can between the can end and the liquid level. The following chart illustrates the width of excess fold required to completely void the vacuum created for various head space heights and volumes in different contempla-ted hot filled cans:
Head Space Height Volume Excess Fold Can Size (Inches) tCubic Inches) (Inches width required) ~02 x 314 (60z.) .125 .416 .467 " " .1875.624 .572 " " .250 .832 .660 " " .3751.247 .810 ~ " .5001.663 933 211 x 413 (120z.) .125 .649 .500 " " .1875.973 .618 " " .2501.297 .715 " " .3751.946 .875 " " .5002.595 1.00 404 x 700 (460z.) .125 1.687 .594 " " .18752.53 .728 " " .250 3.37 .841 " " .375 5.06 1.03 " " .5006.747 1.189 From the foregoing, it will be appreciated that a unique system has been devised for enabling the utilization of composite cans, of basically conventional strength, so as to accommoda-te products wherein a vacuum generated pressure differential is involved. Such a pressure differential, in the conventional can and without the features of the present invention, would, upon the generation of an internal vacuum, ; quite likely cause the can to implode, deform, rupture, leak or otherwise fail. Such problems are avoided by the contemplated provision of a ballooning fold within the liner seam assembly, in conjunction with a container body wall which 0 i5 of substantially constant strength, without lines of weakness, and capable of effectively retaining the product therein in the absence of excess pressure differentials.
In order to insure the structural integrity of the can, and in fact the complete package, specific provision is made to offset the liner seam from the seam or seams of the body ply or plies. In this manner, there is an avoidance of any weakness which might develop because of a stacked alignment . of the seams, notwithstanding the aforementioned intention . that the seams of the body plies be so constructed as to possess 20 an inherent strength equal to that of the body itself remote from the seams thereof.
~ The foregoing is considered illustrative of the ~ principals of the invention. As modifications may occur to those skilled in the art, it is not desired to limit the : invention to the exact embodiment or a manner of construction as shown and described. Accordingly, all suitable modifica-tiGnS and equivalents are considered appropriate within the scope of the invention as claimed.
.,
Claims (10)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a composite container adapted to accommodate a reduced internal pressure, an elongated shape-sustaining body having opposed ends and inner and outer surfaces, a hermetic liner within said body substantially coextensive with and bonded to the inner surface thereof, said liner including an integral inflatable fold formed therein along the length of said body between the opposed ends, said fold being adapted to inwardly balloon relative to the remainder of the liner and the inner surface of the body upon development of a reduced pressure environment within the container, wherein said inflatable fold extends spirally about the inner surface of the body, and wherein said body is cylindrical and of a substantially constant structural strength completely thereabout, and wherein said liner is defined by a spiral wrap of an impermeable liner material, said liner material having opposed overlapped edge portions sealed to each other to provide a continuous hermetic liner about the interior of the cylindrical body, and wherein a first one of said edge portions constitutes an outer edge portion and is bonded to the body, the second edge portion constituting an inner edge portion, said fold being defined along said inner edge portion by a reversely folded edge flap in the outermost portion of said inner edge portion forming an underlying flap with a free edge, said flap directly overlying and being bonded to said outer edge portion, said flap freely underlying the remainder of said inner edge portion whereby said inner edge portion is free to inwardly balloon relative to the bonded outer edge flange.
2. The container of claim 1 wherein said liner is bonded to the inner surface of said body over substantially the full area of engagement with said body other than for a narrow width along and immediately outward of the free edge of the reversely folded edge flap and between this free edge and the overlying second edge portion of the liner to define an air passing opening between the body and the interior of the fold.
3. The container of claim 2 wherein said body is formed of at least one spiral ply of paperbase material having bonded edges offset from the sealed edge portions of the liner.
4. The container of claim 3 wherein the bonded edges of the body ply are of a structural integrity generally equal to that of the remainder of the body.
5. The container of claim 4 wherein the body is formed of multiple body plies, at least one of which has skived bonded edges.
6. The container of claim 1 wherein the body is formed of multiple body plies, at least one of which has skived bonded edges.
7. A method of forming a vacuum accommodating composite can comprising the steps of spirally forming an air impermeable material into a liner defining configuration with overlapped edge portions, including forming an inflatable fold along one of said edge portions by a reverse folding of an outer flap thereof, sealing said reversely folded outer flap solely to the other edge portion while retaining an opening to the interior of the fold along the length thereof, spirally forming a body of paperbase material completely about said liner and in overlying relation to said opening to the interior of the fold, bonding said body to said liner throughout the full area of surface contact between the body and liner except for said opening whereby the generation of a relatively lower pressure within the liner will result in an induced air flow through said body and into the fold to effect an inflation thereof.
8. The method of claim 7 wherein the body is formed with seams therein remote from the liner seam defined by the overlapped edge portions.
9. The method of claim 8 wherein the seams of the body are formed so as to approximate the structural integrity of the remainder of the body.
10. The method of packaging a vacuum generating product within a composite container having a hermetic liner comprising providing a predetermined inwardly inflatable section in the liner, introducing the product into the container with a predetermined head air space being retained, sealing the container, and, coincident with the generation of the vacuum within the container, allowing the inflatable section to inwardly inflate, reducing the volume within the container with the product being accommodated within the head space and the generated vacuum being proportionally reduced.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/131,098 | 1980-03-18 | ||
| US06/131,098 US4343427A (en) | 1980-03-18 | 1980-03-18 | Composite container with balloon fold |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1144880A true CA1144880A (en) | 1983-04-19 |
Family
ID=22447869
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000363100A Expired CA1144880A (en) | 1980-03-18 | 1980-10-23 | Composite container with balloon fold |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US4343427A (en) |
| CA (1) | CA1144880A (en) |
| GB (1) | GB2071601B (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5857613A (en) * | 1990-11-30 | 1999-01-12 | Sonoco Products Company | Easy-open container for refrigerated dough products and the like |
| US5084284A (en) * | 1991-01-07 | 1992-01-28 | The Pillsbury Company | Container for refrigerated dough and method of forming a refrigerated dough product |
| US5251809A (en) * | 1991-08-12 | 1993-10-12 | Sonoco Products Company | Easy-open container for refrigerated dough products and the like |
| US5487506A (en) * | 1994-06-22 | 1996-01-30 | Sonoco Products Company | Easy-open container having an improved reinforcing and tear strip |
| US5494215A (en) * | 1994-06-22 | 1996-02-27 | Sonoco Products Company | Easy-open container having directionally-oriented label tear |
| US5573638A (en) * | 1994-06-27 | 1996-11-12 | Sonoco Products Company | Paperboard for manufacturing single-layer paperboard tube-forming plies |
| US5586963A (en) * | 1994-06-27 | 1996-12-24 | Sonoco Products Company | Single-ply paperboard tube and method of forming same |
| US5851630A (en) * | 1997-01-27 | 1998-12-22 | Westvaco Corporation | Container and blank for "duckbill" elimination |
| US5988493A (en) * | 1998-04-06 | 1999-11-23 | Sonoco Development, Inc. | Composite container for vacuum packaging of products |
| US6422455B1 (en) | 2000-04-05 | 2002-07-23 | Sonoco Development, Inc. | Composite container for vacuum packaging food products such as dough and associated methods |
| US9023445B2 (en) | 2011-10-14 | 2015-05-05 | Kellogg North America Company | Composite containers for storing perishable products |
| US10889403B2 (en) * | 2015-12-10 | 2021-01-12 | General Mills, Inc. | Wound package construct |
Family Cites Families (27)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| USRE21945E (en) | 1941-11-11 | Destructible oil container | ||
| US768107A (en) * | 1903-02-05 | 1904-08-23 | William Erastus Williams | Spirally-wound tube. |
| US1748575A (en) * | 1928-10-19 | 1930-02-25 | Ind Welded Alloys Inc | Lined tank or pressure vessel |
| US2110843A (en) * | 1936-08-07 | 1938-03-08 | Dobeckmun Co | Destructible oil container |
| US2214330A (en) * | 1938-01-19 | 1940-09-10 | Henderson Arthur James | Tank and the like for carrying inflammable spirit on aircraft, ships, vehicles, and the like |
| US2298545A (en) * | 1939-10-19 | 1942-10-13 | Harry F Waters | Coffee package |
| US2367477A (en) * | 1941-01-09 | 1945-01-16 | Harry F Waters | Method of making containers and product thereof |
| US2349730A (en) * | 1941-01-21 | 1944-05-23 | Oswego Falls Corp | Tubular container |
| US2681284A (en) * | 1952-10-02 | 1954-06-15 | Sefton Fibre Can Company | Package of leavened dough |
| US3088624A (en) * | 1959-02-18 | 1963-05-07 | Kaiser Aluminium Chem Corp | Metal foil container |
| US3156401A (en) * | 1960-10-17 | 1964-11-10 | Anaconda Aluminum Co | Container |
| US3201259A (en) * | 1961-04-14 | 1965-08-17 | R C Can Co | Frozen liquid food package and method of making the same |
| US3227352A (en) * | 1961-12-11 | 1966-01-04 | Fibreboard Paper Products Corp | Lined carton |
| US3194471A (en) * | 1964-06-04 | 1965-07-13 | Inland Container Corp | Bulk container device |
| US3279675A (en) * | 1964-09-01 | 1966-10-18 | American Can Co | Spirally wound container body |
| US3406614A (en) * | 1965-06-09 | 1968-10-22 | Reynolds Metals Co | Tubular member and method for making the same and container made therefrom |
| US3315864A (en) * | 1965-06-09 | 1967-04-25 | Reynolds Metals Co | Tubular member and container made therefrom |
| US3397834A (en) * | 1967-03-01 | 1968-08-20 | Container Corp | Rupturable container |
| US3467244A (en) * | 1967-03-10 | 1969-09-16 | Mahaffy & Harder Eng Co | Evacuated package with semirigid shell and flexible closure |
| US3441197A (en) * | 1967-04-10 | 1969-04-29 | American Can Co | Side opening container |
| US3506183A (en) * | 1968-05-21 | 1970-04-14 | Pillsbury Co | Quick opening dough container |
| US4073950A (en) * | 1975-06-25 | 1978-02-14 | The Pillsbury Company | Easy opening spirally wound dough can |
| US3981433A (en) * | 1975-09-15 | 1976-09-21 | Boise Cascade Corporation | One-step easy-open container for refrigerated dough products and the like |
| US3972468A (en) * | 1975-11-28 | 1976-08-03 | The Pillsbury Company | Refrigerated dough can |
| US4091718A (en) * | 1977-01-18 | 1978-05-30 | Boise Cascade Corporation | Method and apparatus for forming composite container including a tab-cut label layer |
| US4158425A (en) * | 1977-12-30 | 1979-06-19 | Sonoco Products Company | Composite container construction |
| US4286745A (en) * | 1979-05-23 | 1981-09-01 | Norton Simon, Inc. | Container for beverages and the like |
-
1980
- 1980-03-18 US US06/131,098 patent/US4343427A/en not_active Expired - Lifetime
- 1980-07-24 GB GB8024270A patent/GB2071601B/en not_active Expired
- 1980-10-23 CA CA000363100A patent/CA1144880A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB2071601A (en) | 1981-09-23 |
| GB2071601B (en) | 1984-06-06 |
| US4343427A (en) | 1982-08-10 |
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Legal Events
| Date | Code | Title | Description |
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| MKEX | Expiry |